Surfactant/solvent systems

ABSTRACT

The present invention relates to surfactant/solvent systems for liquid formulations comprising 
     α) one or more nonaromatic-based surfactants, 
     β) as solvent, one or more triester(s) of phosphoric acid with alcohols, preferably from the group consisting of 
     1 ) monohydric alkanols having 5 to 22 carbon atoms, for example with n-, i- or neo-pentanol, n-hexanol, n-octanol, 2-ethylhexanol, 
     2) diols or polyols, such as ethylene glycol, propylene glycol or glycerol, 
     3) aryl, alkylaryl, poly(alkyl)aryl and poly(arylalkyl)aryl alcohols, for example with phenol and/or cresol, octylphenol, nonylphenol, triisobutylphenol, tristyrylphenol, 
     4) alkoxylated alcohols obtained by reacting the alcohols mentioned above under 1), 2) or 3) with alkylene oxides, preferably (C 1 -C 4 )alkylene oxides, and 
     5) alkoxylated alcohols obtained by reacting monohydric alkanols having 1 to 4 carbon atoms and alkylene oxides. 
     The surfactant/solvent system according to the invention is suitable for the preparation of liquid active substance formulations.

The invention relates to the field of combinations of surfactants andsolvents (surfactant/solvent systems) for liquid formulations of activesubstances (also referred to as liquid preparations), in particular ofagrochemical active substances. The invention preferably relates tosurfactant/solvent systems for one-phase formulations of one or moreagrochemical active substances, where at least one of the activesubstances, preferably each active substance, is not readily soluble inwater. In particular, the invention relates to emulsifiable concentrates(EC) which are based on organic solvents and agrochemical activesubstances of different polarity. Formulations in the form of oil-basedemulsions or suspension concentrates are also possible, and preferenceis given specifically to emulsifiable concentrates which may compriseone or more agrochemical active substances from the group of theherbicides, insecticides, fungicides, acaricides, molluskicides,rodenticides and/or timber preservatives. Preferred in this context are,inter alia, beet herbicides such as desmedipham, phenmedipham,ethofumesate, metamitron and herbicides which are of a similar type withregard to their physical and application properties, for exampleherbicides from the series of the phenoxyphenoxypropionates or of theheteroaryloxyphenoxypropionates.

In general, active substances are employed not as pure materials, but,depending on the field of application and the desired physicalcomposition of the use form, in combination with certain adjuvants, i.e.they are “formulated”. Frequently, such formulations containcombinations of various active substances instead of individual activesubstances to make use, upon application, of the joint properties of theindividual active substances, or else because individual activesubstances are synergistic in combination, i.e. their action is enhancedin a superadditive fashion.

Independently of the type of formulation and of whether the formulationscomprise one or more active substances, the aim in particular in theagricultural sector is to achieve the highest possible active substanceconcentration (“load”) of the formulation in question, since a highconcentration of the active substances permits the application volumesto be reduced, which, as a consequence, saves material with regard tothe adjuvants applied and saves costs in the packaging and transportsector.

Highly concentrated stable formulations and coformulations withenvironmentally friendly adjuvants are therefore interesting as a matterof principle.

In principle, active substances can be formulated in various ways,depending on the biological and/or chemico-physical parametersspecified. In general, examples of suitable formulations which arepossible are wettable powders (WP), oil-in-water (O/W) or water-in-oil(W/O) emulsions, suspensions (SC), suspoemulsions (SE), emulsifiableconcentrates (EC), or else granules for soil application or spreading,or water-dispersible granules (WG). The abovementioned formulation typesare known in principle and are described, for example, in:Winnacker-Küchler, “Chemische Technologie” [Chemical Engineering],Volume 7, C. Hauser-Verlag, Munich, 4^(th) Edition 1986; van Valkenburg,“Pesticide Formulations”, Marcel-Dekker N.Y., 1973; K. Martens, “SprayDrying Handbook”, 3rd Ed., 1979, G. Goodwin Ltd. London.

Liquid formulations of herbicides are already known. Thus, for example,WO-A-85/01286 describes liquid formulations which comprise phenmediphamand/or metamitron. Solvents which are mentioned in this context areesters of polyalcohols, ethers, ketones, water-insoluble alcohols,(poly)glycols and oils of vegetable, but also of mineral, origin, andsuitable emulsifiers mentioned only in general for the above-describedliquid formulations are nonionic, but also ampholytic, cationic oranionic surfactants.

Suitable alternatives to solvent-based emulsifiable concentrates for theabovementioned active substances are inter alia water-containingsuspension concentrates (SC) or suspoemulsions (SE). Such formulationsare described, for example, in EP-A 0514769, WO-A-95/23505, EP-A-0637910and WO-A-92/09195.

FR-A-2597720, FR-A-2599593 and FR-A-2590119 describe emulsifiableconcentrates which—in deviation from the publications citedabove—together with (at least) one herbicide of the biscarbamate type(in particular phenmedipham or desmedipham) comprise a solventcombination of tributyl phosphate and a solvent which is miscible withwater, such as, in particular, N-methylpyrrolidone (NMP).

Furthermore, EP-A-0328217 describes emulsifiable concentrates whichcomprise ethofumesate and, as solvent, tributyl phosphate. Thedisadvantage in the last-mentioned type of formulation is the use oftributyl phosphate because it is considered to be a dangerous chemical(cf., for example, Chemikaliengesetz [German Chemicals Act]). While thisdoes not make impossible, or ban, the use of tributyl phosphate, the useentails, as a rule, conditions or is generally problematic.

Furthermore, it is known that the biological activity of some pesticidalactive substances can be enhanced in some cases by low-molecular weightorganic compounds. Thus, in accordance with BE-A-597284, esters orpartial esters based on orthophosphoric acid and alkyl-, aryl-,alkylaryl-, cycloalkylaryl- and/or heterocycle-based alcohols aresuitable for increasing the action of herbicides, for example herbicidalphenylurea derivatives such as monuron, azoles such as amitrol,triazines such as simazine and propionic acid derivatives such asdalapon. The phosphoric esters specifically described in this context asadjuvants only encompass phosphoric esters which are relatively unpolaror fully soluble in water and which are not suitable for the preparationof emulsifiable concentrates.

DE-A-2914164 describes synergistic effects which are found in the caseof herbicides with a desiccant action on crop plants, i.e. for exampleherbicides from the group of the phenylureas (for example metoxuron,diuron) or triazines (for example atrazine, simazine), when they arecombined with phosphorus-based compositions as are employed inindustrial metallurgy for obtaining metals or as plasticizers forpolymers. It can be seen unambiguously from the publication that thesephosphorus-based compositions, which can be employed for example inindustrial metallurgy for obtaining metals or as plasticizers inpolymers, are employed as active substances in this context and not assolvents. In other words, this means that the phosphoric acidderivatives in this publication are active substances and not solventsor carriers for agrochemical active substances in the traditional sense.It can also be found in the Japanese Patent Specification JA 29878169,that, for example, tributoxyethyl phosphate (TBEP) is described asactive substance, but not as solvent.

Surprisingly, it has now been found that certain surfactant/solventsystems are suitable in a particular manner for use in the preparationof liquid formulations such as oil dispersions, suspoemulsions, W/O- orO/W-based emulsions and, in particular, of emulsifiable concentrates andcorresponding aqueous spray mixtures derived therefrom.

The present invention therefore relates to surfactant/solvent systemsfor liquid formulations (preparations), comprising

α) one or more nonaromatic-based surfactants,

β) as solvent, one or more triester(s) of phosphoric acid with alcohols,preferably from the group consisting of

1) monohydric alkanols having 5 to 22 carbon atoms, for example n-, i-or neo-pentanol, n-hexanol, n-octanol, 2-ethylhexanol,

2) diols or polyols, such as ethylene glycol, propylene glycol orglycerol,

3) aryl, alkylaryl, poly(alkyl)aryl and poly(arylalkyl)aryl alcohols,for example phenol and/or cresol, octylphenol, nonylphenol,triisobutylphenol, tristyrylphenol,

4) alkoxylated alcohols obtained by reacting the alcohols mentionedabove under 1), 2) or 3) with alkylene oxides, preferably(C₁-C₄)alkylene oxides, and

5) alkoxylated alcohols obtained by reacting monohydric alkanols having1 to 4 carbon atoms and alkylene oxides, preferably (C₁-C₄)alkyleneoxides, the triester(s) being insoluble in water or soluble in water ina concentration of up to 10 g/l, preferably up to 5 g/l, in particularup to 2 g/l,

(=surfactant/solvent system according to the invention).

Subject matter of the invention are also liquid active substanceformulations, in particular liquid agrochemical, for example liquidherbicidal, active substance formulations, comprising

(a) one or more active substances, in particular agrochemical, forexample herbicidal, active substances, which are insoluble in water orsoluble in water up to a concentration of 10 g/l,

(b) the surfactant/solvent system according to the invention (=componentmixture (b)),

(c) if appropriate other organic solvents and

(d) if appropriate customary adjuvants and additives such as furthersurfactants, polymers, fertilizers, odorants, evaporation inhibitors,thickeners, colorants, antifreeze agents and/or preservatives, and

(e) if appropriate water.

Nonaromatic-based surfactants α) which are present in thesurfactant/solvent systems according to the invention, are for exampleheterocycle-, olefin-, aliphatic- or cycloaliphatic-based surfactantsα), such as, surface-active pyridine, pyrimidine, triazine, pyrrole,pyrrolidine, furan, thiophene, benzoxazole, benzothiazole and triazolecompounds which are substituted by one or more alkyl groups and aresubsequently derivatized, e.g. alkoxylated, and which are soluble in thesolvent phase are suitable for emulsifying the latter—together withactive substances dissolved therein—upon dilution with water (to give aspray mixture).

Examples of such surfactants α) are listed hereinbelow, EO standing forethylene oxide units, PO for propylene oxide units and BO for butyleneoxide units:

α.1) fatty alcohols having 10-24 carbon atoms with 0-60 EO and/or 0-20PO and/or 0-15 BO in any sequence. The terminal hydroxyl groups of thesecompounds can be end group-capped by an alkyl, cycloalkyl or acylradical having 1-24 carbon atoms. Examples of such compounds are:Genapol® C,L,O,T,UD,UDD,X brands from Clariant, Plurafac® and Lutensol®A,AT,ON,TO brands from BASF, Marlipal® 24 and O13 brands from Condea,Dehypon® brands from Henkel, Ethylan® brands from Akzo-Nobel such asEthylan CD 120.

α.2) Anionic derivatives of the products described under α.1) in theform of ether carboxylates, sulfonates, sulfates and phosphates andtheir inorganic salts (for example alkali metal salts and alkaline earthmetal salts) and organic salts (for example amine- oralkanolamine-based) such as Genapol® LRO, Sandopan® brands,Hostaphat/Hordaphos® brands from Clariant. Copolymers consisting ofEO,PO and/or BO units such as, for example, block copolymers such as thePluronic® brands from BASF and the Synperonic® brands from Uniquema witha molecular weight of 400 to 10⁸. Alkylene oxide adducts of C₁-C₉alcohols such as Atlox® 5000 from Uniquema or Hoe® -S3510 from Clariant.Anionic derivatives of the products described under α.3) and α.4) in theform of ether carboxylates, sulfonates, sulfates and phosphates andtheir inorganic salts (for example alkali metal salts and alkaline earthmetal salts) and organic salts (for example amine- oralkanolamine-based).

α.3) Fatty acid and triglyceride alkoxylates such as the Serdox® NOGbrands from Condea or the Emulsogen® brands from Clariant, salts ofaliphatic, cycloaliphatic and olefinic carboxylic acids andpolycarboxylic acids, and alpha-sulfo-fatty acid esters such as thoseavailable from Henkel.

α.4) Fatty amide alkoxylates such as the Comperlan® brands from Henkelor the Amam® brands from Rhodia. Alkylene oxide adducts of alkyinediolssuch as the Surfynol® brands from Air Products. Sugar derivatives suchas aminosugars and amidosugars from Clariant, glucitols from Clariant,alkyl polyglycosides in the form of the APG® brands from Henkel or suchas sorbitan esters in the form of the Span® or Tween® brands fromUniquema or cyclodextrin esters or cyclodextrin ethers from Wacker.

α.5) Surface-active cellulose and algin, pectin and guar derivativessuch as the Tylose® brands from Clariant, the Manutex® brands from Kelcoand guar derivatives from Cesalpina. Polyol-based alkylene oxideadducts, such as Polyglykol® brands from Clariant. Surface-activepolyglycerides and their derivatives from Clariant.

α.6) Sulfosuccinates, alkanesulfonates, paraffin- and olefinsulfonatessuch as Netzer IS®, Hoe® S1728, Hostapur® OS, Hostapur® SAS fromClariant, Triton® GR7ME and GR5 from Union Carbide, Empimin® brands fromAlbright and Wilson, Marion®-PS65 from Condea.

α.7) Sulfosuccinamates such as the Aerosol® brands from Cytec or theEmpimin® brands from Albright and Wilson.

α.8) Alkylene oxide adducts of fatty amines, quaternary ammoniumcompounds having 8 to 22 carbon atoms (C₈-C₂₂) such as, for example, theGenamin® C,L,O,T brands from Clariant.

α.9) Surface-active, zwitterionic compounds such as taurides, betainesand sulfobetaines in the form of Tegotain® brands from Goldschmidt,Hostapon® T and Arkopon® T brands from Clariant.

α.10) Silicone- or silane-based surface-active compounds such as theTegopren® brands from Goldschmidt and the SE® brands from Wacker andalso the Bevaloid®, Rhodorsil® and Silcolapse® brands from Rhodia (DowCorning, Reliance, GE, Bayer).

α.11) Perfluorinated or polyfluorinated surface-active compounds such asFluowet® brands from Clariant, the Bayowet® brands from Bayer, theZonyl® brands from DuPont and products of this type from Daikin andAsahi Glass.

α.12) Surface-active sulfonamides, for example from Bayer.

α.13) Surface-active polyacrylic and polymethacrylic derivatives such asthe Sokalan® brands from BASF.

α.14) Surface-active polyamides such as modified gelatin or derivatizedpolyaspartic acid from Bayer, and their derivatives.

α.15) Surfactant polyvinyl compounds such as modified PVP, such as theLuviskol® brands from BASF and the Agrimer® brands from ISP or thederivatized polyvinyl acetates such as the Mowilith® brands fromClariant or the polyvinyl butyrates such as the Lutonal® brands fromBASF, the Vinnapas® and the Pioloform® brands from Wacker or modifiedpolyvinyl alcohols such as the Mowiol® brands from Clariant.

α.16) Surface-active polymers based on maleic anhydride and/or reactionproducts of maleic anhydride, and copolymers comprising maleic anhydrideand/or reaction products of maleic anhydride, such as Agrimer®-VEMAbrands from ISP.

α.17) Surface-active derivatives of montan, polyethylene andpolypropylene waxes such as the Hoechst® waxes or the Licowet® brandsfrom Clariant.

α.18) Surface-active phosphonates and phosphinates such as Fluowet®-PLfrom Clairiant.

α.19) Polyhalogenated or perhalogenated surfactants such as, forexample, Emulsogen®-1557 from Clariant.

The solvent component [component (β)] of the surfactant/solvent systemaccording to the invention are fully reacted, unhydrolyzed esters, i.e.triesters, of phosphoric acid, preferably ortho-phosphoric acid withalcohols, which are insoluble in water or soluble in water up to aconcentration of not more than 10 g/l. Compounds which are preferablysuitable as component (β) are those having alkylene oxide units, forexample C₁-C₄-alkylene oxide units, in particular tri(butoxyethyl)phosphate (TBEP). (C₁-C₄)alkylene oxide units, for example ethylenoxy,propyleneoxy and/or butyleneoxy units, in particular propyleneoxy and/orethyleneoxy units, are preferred for alkyleneoxide-units. They arepreferable located in the alcohol component of the phosphoric acidester. Preferred components (β) exhibit 1 to 4 alkylene oxide units,preferably 1 to 4 (C₁-C₄)alkylene oxide units per unit of alcohol. Themolecular weight of the component (β) is preferably smaller than 1000.The compounds of component (β) preferably share the feature that they donot form micellar aggregates in aqueous solutions, for example micellaraggregates which can be detected by light scattering measurements orother methods. This in addition distinguishes them from phosphoric estersurfactants.

Suitable components (β) are the esters of phosphoric acid, e.g.orthophosphoric acid which has been formally reacted three times withalcohols, and the oxalkylates of phosphoric acid, e.g. orthophosphoricacid, which has been formally reacted once and/or twice with alcohols.Examples of suitable compounds are tri-esters of phosphoric acid withalcohols from the group consisting of

1) monohydric alkanols having 5 to 22 carbon atoms, for example with n-,i- or neo-pentanol, n-hexanol, n-octanol, 2-ethylhexanol,

2) diols or polyols, such as ethylene glycol, propylene glycol orglycerol,

3) aryl, alkylaryl, poly(alkyl)aryl and poly(arylalkyl)aryl alcohols,for example with phenol and/or cresol, octylphenol, nonylphenol,triisobutylphenol, tristyrylphenol,

4) alkoxylated alcohols obtained by reacting the alcohols mentionedabove under 1), 2) or 3) with alkylene oxides, preferably 1 to 4 unitsof (C₁-C₄)alkylene oxides, and

5) alkoxylated alcohols obtained by reacting monohydric alkanols having1 to 4 carbon atoms and alkylene oxides, preferably 1 to 4 units of(C₁-C₄)alkylene oxides, which esters are substantially insoluble inwater.

Preferred phosphoric esters (component β) are, for example,

alkoxylated short-chain alcohols having 1-22 carbon atoms in the alkylradical and 1 to 30, preferably 1 to 4 alkyleneoxide units in thepolyalkyleneoxy moiety which have been reacted completely withortho-phosphoric acid, for example tributoxyethyl phosphate,

alkyl alcohols having 5-22 carbon atoms which have been reactedcompletely with ortho-phosphoric acid, for example Hostaphat CG 120®(Clariant), tri-n-octyl phosphate (“TOF”, Bayer), and

optionally alkoxylated alcohols having 1-22 carbon atoms in the alkylradical and phenol derivatives which have been partially reacted withortho-phosphoric acid, in each case with 0 to 30, preferably 0 to 4alkyleneoxide units in the polyalkyleneoxide moiety, the remaining OHvalencies of the ortho-phosphoric acid subsequently having beenalkoxylated, for example the reaction product of mono/dibutoxyethylphosphate and 2 mol of ethylene oxide or 2 mol of propylene oxide.

Surprisingly, the surfactant/solvent system according to the inventionallows stable active substance formulations to be prepared, for exampleformulations of active substances, in particular agrochemical, forexample herbicidal, active substances which are insoluble in water orsoluble in water up to a concentration of 10 g/l. Examples of suchactive substance formulations are visually transparent andthermodynamically stable emulsifiable concentrates, thermodynamicallyunstable O/W and W/O emulsions, suspoemulsions or suspensionconcentrates, inter alia of agrochemical, preferably herbicidal, activesubstances such as biscarbamate herbicides (for example desmediphamand/or phenmedipham), and/or sulfonate herbicides (for exampleethofumesate) and/or triazinone herbicides (for example metamitron). Inaddition, the surfactant system according to the invention may have afavorable effect on the pesticidal action of the agrochemical activesubstance(s) incorporated.

Also, the surfactant/solvent system according to the invention permitsthe preparation of formulations with active substances other than thosementioned above as long as they have similar properties with regard totheir solubility. For example, others which are suitable are herbicidesfrom the group of the phenoxyphenoxypropionates such as diclofop-methyl,of the heteroaryloxyphenoxy-propionates such as fenoxaprop-ethyl orclodinafop-propargyl, of the triazinones, such as metamitron, of thesulfonylureas, such as triflusulfuron-methyl, or other active substancessuch as prochloraz and/or insecticides such as deltamethrin. This showsthe flexibility of the surfactant/solvent system described. Thecompounds mentioned are known to the skilled worker for example from“The Pesticide Manual”, British Crop Protection Council, 11^(th)edition, 1997.

Other organic solvents (c) which are suitable are, for example, unpolarsolvents, polar protic or aprotic dipolar solvents and their mixtures.Examples of other organic solvents for the purposes of the invention are

aliphatic or aromatic hydrocarbons such as, for example, mineral oils,paraffins or toluene, xylenes and naphthalene derivatives, in particular1-methylnaphthalene, 2-methylnaphthalene, mixtures of C₆-C₁₆-aromaticssuch as, for example, the Solvesso® series (ESSO) with the typesSolvesso® 100 (b.p. 162-177° C.), Solvesso® 150 (b.p. 187-207° C.) andSolvesso® 200 (b.p. 219-282° C.) and 6-20C aliphatics which can belinear or cyclic, such as the products of the Shellsol® series, types Tand K, or BP-n paraffins,

halogenated aliphatic or aromatic hydrocarbons such as methylenechloride or chlorobenzene,

mono- and/or polybasic esters such as, for example, triacetin (aceticacid tri(lyceride), butyrolactone, propylene carbonate, triethyl citrateand (C₁-C₂₂)alkyl phthalates, specifically (C₄-C₈)alkyl phthalates,

ethers such as diethyl ether, tetrahydrofuran (THF), dioxane, alkyleneglycol monoalkyl ethers and alkylene glycol dialkyl ethers such as, forexample, propylene glycol monomethyl ether, specifically Dowanol® PM(propylene glycol monomethyl ether), propylene glycol monoethyl ether,ethylene glycol monomethyl ether or ethylene glycol monoethyl ether,diglyme and tetraglyme,

amides such as dimethylformamide (DMF), dimethylacetamide,dimethylcaprylic/capric amide and N-alkylpyrrolidones,

ketones such as acetone, which is water-soluble, but also ketones whichare not miscible with water, such as, for example, cyclohexanone orisophorone,

nitriles such as acetonitrile, propionitrile, butyronitrile andbenzonitrile,

sulfoxides and sulfones such as dimethyl sulfoxide (DMSO) and sulfolane,and

oils in general, for example vegetable oils such as corn oil andrapeseed oil.

Further preferred organic solvents for the purposes of the presentinvention are, in particular, amides such as dimethylcaprylic/capricamide and N-methylpyrrolidone, or aromatic solvents such as theSolvesso® series from Exxon.

The adjuvants and additives used for the preparation of theabovementioned formulations, such as, in particular, surfactants andsolvents, are known in principle, and are described, for example, instandard works: McCutcheon's “Detergents and Emulsifiers Annual”, MCPubl. Corp., Ridgewood N.J.; Sisley and Wood, “Encyclopedia of Surfaceactive Agents”, Chem. Publ. Co. Inc., N.Y. 1964; Schönfeldt,“Grenzflächenaktive Äthylenoxidaddukte” [Surface-active ethylene oxideadducts], Wiss. Verlagsgesellschaft, Stuttgart 1976; Winnacker-Küchler,“Chemische Technologie” [Chemical Engineeering], Volume 7, C.Hauser-Verlag, Munich, 4^(th) edition, 1986.

While the chemical structure of the individual components which can beemployed is described in sufficient detail in the abovementionedstandard works, predictions regarding the properties of mixtures of suchcomponents for formulating an active substance cannot be deduced fromthe abovementioned standard works.

Surprisingly, it has now been found that combinations of an in waterinsoluble or up to 10 g/l in water soluble phosphoric-acid tri-ester assolvent and one or more nonaromatic-based surfactants are particularlywell suited for the preparation of liquid formulations of activesubstances such as stable emulsifiable concentrates, emulsions,suspoemulsions or suspension concentrates, which are also an object ofthe present invention.

The liquid formulations according to the invention can be prepared bythe customary processes which are already known, for example by mixingthe various components with the aid of stirring, shaking or (static)mixers. If appropriate, it is advantageous to briefly heat the samplesin order to ensure the complete dissolution of all the componentsinvolved.

One factor for the selection of preferred surfactant components is theiracidity or basicity per unit weight or volume, which is expressed, forexample, by the acid number or amine number. When selecting furthersurfactant components, it is advantageous to ensure that the total acidnumber or amine number does not increase unduly. Preferably suitable,besides nonionic surfactants, are therefore for example acidic or basicsurfactant components with sufficiently small acid or amine numbers, ornonionic surfactant components. Accordingly, additional nonionicsurfactant components which can be employed are, for example, castor oilwhich has been reacted with 40 mol of EO or else castor oil which hasbeen reacted with 12 mol of EO, oleic acid which has been reacted with15 mol of EO, and EO/PO/EO block copolymers.

In this connection it must furthermore be mentioned that thesurfactant/solvent systems of the present invention allow thepreparation of stable formulations with an active substance load andactive substance composition which can be varied within wide limits.Thus, the active substance load may vary for instance between 20 and 40,preferably between 24 and 30, percent by weight. As regards the activesubstance composition, not only stable formulations with one activesubstance, but also formulations with two or, in particular, threeactive substances, can be obtained using this component mixture.

The above-described surfactant/solvent systems are preferably suitablefor the preparation of formulations with herbicidal active substancessuch as diclofop-methyl, fenoxaprop-ethyl, prochloraz, metamitron and/ordeltamethrin.

Preferred ratios of the components phosphoric ester (β):surfactant (α)are, in particular, 100:1 to 1:100, especially preferably 1:5 to 1:20,for example approximately 1:8, 1:9 or 1:10, or 1:0.,25 to 1:0.,9, forexample 1.3:1, 1.4:1 or 1.5:1, depending on the active substance loadand the active substance composition of the formulations.

The surfactant/solvent system according to the invention permits thepreparation of various liquid formulations, such as oil dispersions,suspoemulsions, W/O- or O/W-based emulsions and, in particular, ofemulsifiable concentrates and corresponding liquid formulations derivedtherefrom, such as aqueous spray mixtures.

Emulsifiable concentrates which are prepared in accordance with thepresent invention comprise a priori no added water, but only theresidual water present in the abovementioned commercially availablesurfactants and surfactant mixtures, polymers and solvents. Owing to thesurfactants present in the emulsifiable concentrates of the presentinvention, however, it is possible for these to be diluted with water asfar as a critical volume fraction without this leading to cloudiness orthe formulation becoming unstable. Formally, this first gives rise toW/O microemulsions which, upon further increasing the water fraction,become W/O emulsions and finally —upon further dilution with water—O/Wemulsions. The invention therefore also encompasses liquid formulationswhich, besides the surfactant/solvent mixture b) according to theinvention, comprise (added) water, for example microemulsions.

The component mixtures (b) allow preferably liquid preparations ofactive substances, in particular herbicidal active substances such asdesmedipham and/or phenmedipham and/or ethofumesate, to be prepared,which comprise

a) 1 to 50% by weight, preferably 15 to 35% by weight, of agrochemicalactive substances,

b) 5 to 80% by weight, preferably 10 to 70% by weight, of thesurfactant/solvent system (b) according to the invention,

c) 0 to 40% by weight, preferably 5 to 35% by weight, of further organicsolvents,

d) 0 to 20% by weight, preferably 0 to 10% by weight, of customaryadjiuvants and additives, such as formulation auxiliaries, and

e) 0 to 96% by weight, preferably 0 to 90% by weight, in particular 0 to10% by weight, of water.

Examples of customary adjiuvants and additives such as formulationauxiliaries d) are antifreeze agents, evaporation inhibitors,preservatives, odorants and colorants. Preferred formulation auxiliariesd) are antifreeze agents and evaporation inhibitors such as glycerol,for example in an amount of 2 to 10% by weight, and preservatives, forexample Mergal K9N® (Riedel) or Cobate C® in the use concentrationswhich are customary for the agents employed in each case.

Since anhydrous emulsfiable concentrates constitute an advantageous useform of the active substances, in particular herbicidal activesubstances of type (a), an especially preferred subject matter of theinvention are emulsifiable concentrates which comprise

a) 10 to 40% by weight of active substances of the abovementioned type(a),

b) 10 to 60% by weight of the surfactant/solvent system (b) according tothe invention,

c) 5 to 35% by weight of further organic solvents and

d) 0 to 10% by weight of customary adjuvants and additives, for exampleformulation auxiliaries.

In analogy to anhydrous emulsfiable concentrates, the oil-basedsuspension concentrates, which are likewise anhydrous, constitute apreferred subject matter of this invention, these preparationscomprising

a) 10 to 40% by weight of active substances of the abovementioned type(a),

b) 10 to 60% by weight of the surfactant/solvent system (b) according tothe invention,

c) 5 to 35% by weight of further organic solvents,

d) 0 to 10% by weight of customary adjuvants and additives other than(e), such as formulation auxiliaries, and

e) 0.001 to 20% by weight of organic and/or inorganic thickeners.

Furthermore, emulsions may also be prepared with the surfactant/solventsystems according to the invention. A further especially preferredsubject matter of the invention are therefore emulsions ormicroemulsions comprising

a) 10 to 40% by weight of active substances of the abovementioned type(a),

b) 10 to 60% by weight of the surfactant/solvent system (b) according tothe invention,

c) 5 to 35% by weight of further organic solvents and

d) 0 to 10% by weight of customary adjuvants and additives, such asformulation auxiliaries and

e) 0.001 to 95% by weight of water.

The suspoemulsions which can be prepared with the above-describedsurfactant/solvent systems also constitute a preferred subject matter ofthe invention. These comprise

a) 10 to 40% by weight of active substances of the abovementioned type(a),

b) 10 to 60% by weight of the surfactant/solvent system (b) according tothe invention,

c) 5 to 35% by weight of further organic solvents and

d) 0 to 10% by weight of customary adjuvants and additives other than(f), such as formulation auxiliaries and

e) 0.001 to 95% by weight of water and

f) 0.001 to 20% by weight of organic and/or inorganic thickeners.

Upon dilution with water, the surfactant/solvent system according to theinvention (component mixture b)) results in dispersions of oil phases inwater or, when the appropriate individual components have been chosen,of aqueous phases in oil. Accordingly, dispersions can be obtained whichcan be diluted either with water or with oil while retaining thecolloidal structure, depending on the composition. The dispersions whichcan be obtained from the above-described concentrates by dilution aretherefore another subject matter of the invention.

The surfactant/solvent system according to the invention is suitable forthe preparation of stable liquid formulations, in particularemulsifiable concentrates. The formulations and spray mixtures which canbe prepared with the surfactant/solvent system according to theinvention also give results which are advantageous from the biologicalangle upon use. An effective amount of the formulation or of the spraymixture, if necessary after dilution with water, is applied to theplants, plant parts or the area on which the plants grow, for examplethe area under cultivation. Moreover, the biological activity of theagrochemical active substances employed can be increased synergisticallyby employing the surfactant/solvent component b) according to theinvention.

EXAMPLES

In the examples which follow, stated quantities are based on weightunless otherwise specified. The examples of Table 1 refer to comparativeexamples not in accordance with the invention, while the examples ofTable 2 are in accordance with the invention and describe emulsifiableconcentrates (Examples I-VII), emulsions (Examples VIII and XI),suspoemulsions (Example IX) and suspension concentrates (Example X). Theformulations were prepared by mixing the components with a stirrer.

TABLE 1 Example of formulations which give no stable emulsifiableconcentrates (EC) 1 2 3 4 Fenoxaprop-p-ethyl 15 Endosulfan 40Deltamethrin 5 Metamitron 1 Rapeseed oil 27 40 57 30 Genapol X-060⁴⁾ 1520 20 30 Emulsogen EL-400⁵⁾ 14 19 18 25 Phosfetal 201⁸⁾ 4 4 4 10Servoxyl VPDZ 20/100⁷⁾ 2

TABLE 2 Examples of formulations according to the invention which givestable formulations I II III IV V VI VII VIII IX X XI Ethofumesate 12.538.4 10.5 13.7 15.8 10.5 Phenmedipham 10.0 8.5 11.1 12.8 8.5 Desmedipham8.0 6.5 8.5 9.8 6.5 Diclofop-methyl 15.0 Fenoxaprop-p-ethyl 15.0Prochloraz 40.0 Deltamethrin 5.0 Metamitron 1.5 Tributoxyethylphosphate¹⁾ 25.5 40.0 40.0 27.0 45.0 21.6 42.5 27.5 12.6 12.0 22.5Rapeseed oil 9.8 Genapol X-060⁴⁾ 20.0 20.0 20.0 15.0 20.0 20.0 27.0 15.015.0 20.0 15.0 Genapol PF 20⁶⁾ 10.0 9.8 14.0 Emulsogen EL 400⁵⁾ 18.0 1919.0 14.0 20.0 16.0 24.0 12.0 Phosfetal 201⁸⁾ 4.0 4.0 4.0 4.0 10.0 4.05.0 5.0 3.0 Servoxyl VPDZ 20/100⁷⁾ 2.0 2.0 2.0 HOE S3618²⁾ 2.5 2.5 3.0Bentone 38³⁾ 0.8 Drinking water 19.5 26.8 19.0 Explanations for Tables 1and 2: ¹⁾Tributoxyethyl phosphate (specifically Hostaphat B310 ®,Clariant) ²⁾Neutralized, phosphated ethylene oxide/propyleneoxide/ethylene oxide block copolymer (specifically HOE ®S3618, Clariant)³⁾Silica derivative (specifically Bentone ®38) ⁴⁾Ethoxylated i-C₁₃-fattyalcohol (specifically Genapol X-060 ®, Clariant) ⁵⁾Ethoxylated castoroil (specifically Emulsogen EL 400 ®, Clariant) ⁶⁾Ethyleneoxide/propylene oxide/ethylene oxide block copolymer (specificallyGenapol PF 20 ®, Clariant) ⁷⁾Phosphated ethoxylated isotridecyl alcohol(specifically Servoxyl VPDZ 20/100°®, Condea) ⁸⁾Phosphated ethoxylatedfatty alcohol (specifically Phosfetal 201 ®, Zschimmer&Schwarz)

We claim:
 1. A liquid active substance formulation which comprises (a)one or more active substances which are insoluble in water or soluble upto a concentration of 10 g/l, selected from the group consisting ofbiscarbamate herbicides, sulfonate herbicides, triazinone herbicides,phenoxyphenoxypropionates, heteroaryloxyphenoxypropionates andsulfonylureas, and (b) a surfactant/solvent system comprising α one ormore nonaromatic-based surfactants, and β as solvent, tri(butoxy ethyl)phosphate.
 2. A liquid active substance formulation as claimed in claim1, additionally comprising (d) further organic solvents, (e) furtheradjuvants and additives, (f) water.
 3. The liquid active substanceformulation of claim 2, wherein said further adjuvants and additives areselected from the group consisting of surfactants, polymers, andmixtures thereof.
 4. A liquid active substance formulation as claimed inclaim 1, which comprises a) 1 to 50% by weight of at least one activesubstance, b) 5 to 80% by weight of the surfactant/solvent system, c) 0to 40% by weight of further organic solvents, d) 0 to 20% by weight ofcustomary adjuvants and additives other than (f), e) 0 to 96% by weightof water, and f) 0 to 30% by weight of further surfactants.
 5. A liquidactive substance formulation as claimed in claim 1 in the form of anemulsifiable concentrate.
 6. An emulsifiable concentrate as claimed inclaim 5 which comprises a) 10 to 40% by weight of active substances, b)10 to 60% by weight of the surfactant/solvent system, c) 5 to 35% byweight of further organic solvents, d) 0 to 10% by weight of customaryadjuvants and additives other than (e), and e) 10 to 25% by weight offurther surfactants.
 7. A liquid active substance formulation as claimedin claim 1, which comprises one or more active substances selected fromthe group consisting of desmedipham, phenmedipham and ethofumesate.
 8. Aprocess for the preparation of an active substance formulation asdefined in claim 1, wherein the components are mixed with each other.